Method of making expanded metal gratings



F. A. GRUETJEN METHOD OF MAKING EXPANDED METAL GRATINGS Filed March 31, 1947 Sept. 9, 1952 3 Sheets-Sheet l gwmvrozz. I 4 fi'eclerzckAGrue n ATTORNEY.

Sept. 9, 1952 F. A. GRUETJEN METHOD OF MAKING EXPANDED METAL GRATINGS Filed March 31, 1947 3 Sheets-Sheet 2 INVEN TOR. FrederickAGruei en ATTORNEY p 9, 1952 F. A. GRUETJEN 2,609,781

METHOD OF MAKING EXPANDED METAL GRATINGS Filed March 51, 1947 3 Sheets-Sheet 3 INVENTOR.

Frederrck AGruef en 4 fimmm AT TORNEY.

Patentecl Sept. 9, 1952 METHOD or MAKING EXPANDED METAL GRATINGS Frederick A. Gruetjen, Milwaukee, Wis, assignor to A. 0. Smith Corporation, Milwaukee, Wis., a corporation of New York Application March 31, 1947, Serial No. 738,255

3 Claims.

This invention relates to method of making expanded metal grating such as grating to be employed as a tread or walkway for railroad freight cars and the like.

One object of the invention is to provide an expanded metal grating in which the bond or tread surface is substantially vertical.

Another object is to provide a method of making an expanded metal grating in which the tread is provided with teeth in the initial cutting of the metal before expansion of the same.

A further object of the invention is to provide a grating at considerably less cost than previous gratings.

A further object is to provide a metal walkway of substantial rigidity with a decrease in metal and weight over previous constructions.

A further object is to provide a metal grating with integral longitudinal side bars.

Another object of the invention is to provide an improved method for fabricating a metal grating and which has integral side bars.

These and other objects of the invention will appear hereinafter in connection with the follow ing description of an embodiment of the invention as illustrated in the accompanying drawings.

In the drawings: 7

Figure 1 is a plan view of the completed grat- 7 Fig. 2 is an elevational view of the side of the grating first formed in making the grating;

Fig. 3 is an elevational view of the side of the grating last formed in making a grating;

Fig. 4 is an enlarged section taken on line 4 1 of Fig. 1;

Fig. 5 is an enlarged section taken on line 5-5 of Fig. 1;

Fig. 6 is a perspective view of a portion of the completed grating;

Fig. '7 is a top plan view of the first step of theoperation;

Fig. 8 is a front side elevation of Fig. '7 showing the table and cutting dies;

Fig. 9 is a top plan view of the second. step of the operation showing the cutting dies in section; Fig. 10 is a front side elevation of Fig. 9;

Fig. llis a side elevational view showing the sheet after successive forming steps;

Fig. 12 is a top plan view of the finished sheeting after completion of the last cutting and form ing operation;

Fig. 13 is a fragmentary perspective View of Fig. 12; a

Fig. it is an end elevational View showing the sheeting in place on a slotted die ready to be rectified into the grating oi the invention;

Fig. 15 is an end elevational view showing the rectifying of the treads to vertical position; and

Figs. 16 and 17 are detail views showing the upsetting of the first formed edge into bar and tread alignment, shown in Fig. 2'.

Inthe drawings there is shown an expanded metal grating or walkway, the body portion of which comprises a plurality of horizontal rows of transversely spaced vertical bonds or treads i with each row of treadsofiset or staggered from the adjacent rows, and treads I of one row integrally connectedto the offset treads of the next adjacent rows by the diagonally extending strands 2 to provide the grating with a plurality of hexagonal shaped openings 3. Strands 2 are slightly twisted in fabrication and each strand 2 is approximately one-half the cross-section of a tread I. Of a pair of strands extending between treads I, one strand extends from the bottom of one tread in the one row to the top of the tread in the next adjacentrow while the other strand 2 in the first mentioned row extends from the top of the tread thereof to the bottom of thetread in the other next adjacent row.

The grating is bounded on one longitudinal side by the integrally formed vertical bar 4 and on the opposite longitudinal side with the integrally formed vertical bar 5. Bars 4 and 5 are connected to treads i by the integral strands 2 corresponding to the strands in the body of the grating.

Bar 4 is provided with the longitudinally spaced treads 6 corresponding in cross-section to treads I of the body of the grating and having the same vertical cross-section as treads I. Treads 8 of bar 4 are spaced from the nearest treads I of the body of the grating by vertical openings 3 as are pro vided in the body of the grating.

The treads lof bar 4 are longitudinally spaced in bar 4 between treads 6 therein and are trans versely spaced from the nearest treads I of the grating by vertical openings 8 which are approximately one-half the cross-section of vertical openings 3 previously described.

Treads I of bar 4 are approximately one-half the cross-section of treads I and 6 and an upset operation, as will be described, is employed on treads I in fabrication to provide treads i as a part of the common tread surface of the grating and also to take up the metal at the forward side of the grating in the initial expanding operation to be described.

Bar 5 provides a continuous longitudinal tread surface with alternate portions of bar 5 corresponding to the cross-section of treads I and d and intermediate portions thereof being about one-half the cross-section of treads I and 5 and corresponding to treads I of bar 4.

Teeth 9 are provided in the upper edge of treads I, 6 and I, respectively, to make the treads on the a grating non-slip in service.

End bars I0 closethe grating on each end and have suitable apertures II to receive the tabs I2 on the ends of the bars 4 and 5, and the end treads I of the body portion'of the grating.

Tabs I2 are bent over against the outer sur- Under one method of making the grating the fiat metal sheet I3 which is to be expanded is first provided with tabs I2 on oppostie ends at predetermined spaced positions. shown on fiat sheet I3 in Fig. '7 and the method of cutting the tabs is not shown in the drawings as it forms no part of the present invention.

Sheet I3 is then placed on a table I4 with the working edge at one side, and suitable means, not shown, is provided to move sheet I3 forwardly and sidewardly in the fabricating operation, as will be described.

Sheet I3 is initiall moved forwardly on table HI to a line where the longitudinal side portion which forms bar 4 of the grating projects from the table about half the height of a tread I and the sheet is then engaged at the working edge of the table by the downwardly moving longitudinally spaced cutter dies I5, the end view of one such die being shown in Fig. 11.

Dies I5 cut a plurality ofspaced longitudinal slots It, as shown in Fig. 7, in'sheet I3 in line with the first tabs I2 on the opposite sides of the sheet and previously provided thereon as described. In cutting slots I6, the die also cuts teeth 9 in the sheet centrally of slots I 6 which latter appear on treads of bar 4 as the tread surface. In cutting slots IS, the dies depress or expand the longitudinal side portion of sheet I3 to a lower plane than the body of the sheet, as shown in Fig. 8, to form a portion of bar 1 when the sheet is finally fabricated into a grating.

Sheet I3 is next moved sidewardly and then forwardly on table I4 and a second row of spaced longitudinal slots I"! with teeth 9, as shown in Fig. 9, are cut therein at the edge of table It by the downwardly moving die cutters I5. Slots I! are located on a line equally spaced between the first and second tabs I2 of the sheet. Slots II are also offset or staggered from slots I6 due to the sideward movement of the sheet described, before the same is moved forwardly. As the cutter dies l5 move downwardly to form slots II, the portions between slots I6 and I7 and in advance of slot I! are depressed or expanded to a lower plane, as shown in Fig. 10. Strands 2 join the treads 6, formed by cutting slots I1, to the sheet.

Sheet i3 is next moved sidewardly on table It back to the transverse position where slots I6 were cut and then forwardly to cut an additional row of slots in line with slots I6 but offset from slots I'I.

Thereafter sheet I3 is alternately shifted sidewardly and forwardly, as described, with first one row of slots being cut and intermediate portions of the sheet between the rows of slots being depressed by cutter dies I5, followed by another row of slots being cut at locations offset from the previous row of slots and intermediate portions of the sheet being depressed until the rear end of the sheet is within approximately half a tread height from the cutting die, as shown in Fig. 12. Fig. 11 is a side elevational view showing sheet I3 after a number of successive forming steps.

In the final cutting and depressing operation on sheet I3, the slots I 8 are cut in the same manner as slots I6 and I1 and the intermediate portions of the sheet between slots I8 and the previously cut slots are depressed, as shown in Fig. 13. The side longitudinal portion I9 of sheet I3 is held on table I 4 by suitable means and in the final forming of the grating, to be described, portion I9 becomes side bar 5 with the latter being connected to the treads I by strands 2.

The formed sheet I3 is finally fabricated into the grating 0f the invention by a rectifying operation under which the tread portions and bars of Tabs I2 are the grating are straightened to a vertical position and strands 2 are slightly twisted.

In the rectifying operation the slotted sheet is placed on die 20, as shown in Fig. 14, with the side which becomes the bottom of the grating in service faced upwardly and the upper die 2I is brought into contact with treads I of the body portion of the grating and the longitudinal side portions. Die 2| moves the treads and side portions downwardly into the vertical spaced slots 22 of lower die 20 to straighten the treads to vertical position with the side portions forming longitudinal bars 4 and 5.

The grating is removed from dies 28 and 2i and the tread portions I on bar 4 are then upset to align with the treads I and 6, as shown in Figs. 16 and 17, to form a common tread surface throughout the grating by treads I, 6 and I, respectively, and the longitudinal extending tread of bar 5.

End bars IE] are next assembled to the grating by inserting tabs I2 on the grating through suitable holes I I in end bars I0 and then turning the tabs against the outer face of each bar. The tabs may be welded to the bars by electric resistance welding. Lugs, not shown, may be welded to the bottom of the grating to bolt the same in place.

The invention provides a generally lightweight grating of sufficient strength and rigidity to stand up effectively under service requirements.

The invention also provides a method of providing integral longitudinal side bars and vertical treads which form a good footing in the common tread surface of the grating on which there is no danger of tripping. I

Various embodiments of the invention may be employed within the scope of the accompanying claims.

I claim: I

l. The method of forming a gratin from expanded metal, which comprises cutting offset longitudinal slots in flat metal sheeting and expanding the sheeting to form rows of bond portions and side bars integrally joined by strands extending therebetween, subjecting the bond and bars to a forming operation to rectify the same to a vertical position and to provide a common tread surface thereof, and upsetting intermediate portions of the first formed bar of the grating to bring said portions into the plane of the common tread surface of the grating.

2. In the method of forming integral side bars on grating formed from expanded metal sheeting by cutting slots therein and expanding and rectifying the uncut portions of the sheeting ahead of said slots to provide vertical treads therein on a common plane, the steps comprisin cutting the last row of slots at a line removed from the rear edge of the grating about one-half the height of a tread of the completed grating to leave the rear edge portion of the sheeting as one side bar of the grating, turning said formed sheeting over and upsetting the forward edge portions of the sheeting ahead of the slots first cut in the sheeting in the direction of the common plane of the treads to form the same as a part thereof and complete the forward edge as another side bar of the grating.

3. The method of forming a grating from'expanded metal sheeting with said grating having integral side bars, which comprises cutting a plurality of spaced longitudinal slots in said sheeting near the forward edge thereof and expanding the edge portion of said sheeting ahead of said slots, cutting a second row of spaced longitudinal slots offset and spaced from said first row of slots and expanding the portions of the sheeting intermediate the first and second row of slots and ahead of the second row of slots, then successively cutting rows of slots in said sheeting with each row of slots offset from the previously cut row and expanding the sheeting ahead of the slots last cut until the last row of slots is cut adjacent the rear edge of the sheeting leaving the rear edge portion free to form a side bar of the grating, operating on said grating to rectify the uncut portions of said grating to a generally vertical position to form a common tread surface,

and upsetting the forward edge portion of said sheeting ahead of the slots first out therein to bring the same into the plane of the portions of the grating forming the common tread surface thereof.

FREDERICK A. GRUETJEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

